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Network Analysis about Study on the Oral Health of People with Disabilities
J Dent Hyg Sci 2024;24:107-14
Published online June 30, 2024;
© 2024 Korean Society of Dental Hygiene Science.

Seol-Hee Kim

Department of Dental Hygiene, College of Medical Science, Konyang University, Daejeon 35365, Korea
Correspondence to: Seol-Hee Kim,
Department of Dental Hygiene, College of Medical Science, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
Tel: +82-42-600-8449, Fax: +82-42-600-8408, E-mail:
Received June 3, 2024; Revised June 14, 2024; Accepted June 18, 2024.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background: This study aimed to analyze trends in oral health research among people with disabilities.
Methods: Data were obtained from 70 oral studies on individuals with disabilities from 2000 to 2024. Keywords were analyzed. Frequency, betweenness centrality, and cluster analyses were performed using NetMiner.
Results: The main keywords for oral health research on disabled people were oral health, dental caries, DMFT (decayed-missing-filled-teeth), dental treatment, oral health centers, and disabled children. As a result of the centrality analysis, DMFT had the highest connectivity, followed by disabled children, special care dentistry, oral health behavior, periodontitis, and health insurance. Cluster analysis results of research on disabled people: Group 1, oral diseases and functions of disabled people; Group 2, oral care for disabled children; Group 3, dental treatment for disabled people; Group 4, oral health policy; Group 5, oral care by dental hygienists; and Group 6, conservative dentistry.
Conclusion: Considering the increase in the number of disabled people in a super-aging society, research on ways to promote oral health for disabled people, oral health policies, and training of oral health experts for disabled people is required.
Keywords : Cluster analysis, Dental care, Disabled persons, Oral health, Preventive dentistry


According to a survey on the status of people with disabilities, 90% of disabilities were acquired due to diseases, accidents, etc. As the older population increases, the number of people with disabilities also increases1). The physical, mental, and social health problems experienced by people with disabilities are no longer presented as individual problems but as social problems2). In particular, oral health dysfunction has a negative impact on overall health owing to impaired nutritional intake through mastication and swallowing. Daily oral care is essential to maintain oral function. Disabled individuals experience difficulties in self-administering oral care and require help from guardians. The dental biofilm index and prevalence of oral diseases are higher in people with disabilities than in those without3). However, people with disabilities avoid dental treatment because of difficulties in communication, high anxiety about dental treatment, behavioral control problems4), burden of treatment costs due to financial difficulties, and cold treatment from medical staff5). Dental medical institutions avoid treating people with disabilities due to problems with behavioral control, general anesthesia, dental treatment, and follow-up care6); high difficulty and risk of treatment; and lack of facilities7).

The number of dental medical institutions for people with disabilities in South Korea is 70 of 255 public health centers nationwide. There is only one accessible tertiary medical institution for people with disabilities in each region8). Recently, the government introduced an attending physician system for individuals with disabilities, allowing dentists to complete training in managing chronic diseases or health9). Doctors participating in the treatment of patients with disabilities completed oral care training according to the type of disability and had volunteer experience2). To encourage participation in oral healthcare for individuals with disabilities, there is a need to expand the education and clinical field experience of dentists and dental hygienists on oral health for the disabled through university education. In addition, compared with research on children and the elderly, research on oral status surveys and oral health policies for people with disabilities is insufficient and requires further improvement. Existing studies related to the oral cavity of the disabled include dental treatment and follow-up care under general anesthesia6), changes in the oral health status of the elderly with hearing and visual impairment due to home-visit oral care interventions10), the role of local oral care centers for the disabled, and the appropriateness of dedicated dental hygienists. It has been conducted on a variety of topics, including the consideration of roles11), reasons for unmet dental care for people with disabilities12), and eating disorders in autism spectrum disorder13). However, the systematicity and sustainability of this study were insufficient. Consequently, there are limitations in pursuing changes in oral health policies for the disabled, treatment guidelines, training of professional personnel, and medical services required by the disabled. Therefore, it is necessary to analyze research trends related to the oral health of people with disabilities and to present the basic data needed to improve their oral health. Therefore, network analysis can be used. Network analysis confirms the organic relationships between keywords and identifies research trends through centrality and cluster structure analyses.


Accordingly, we conducted a network analysis of studies related to the oral cavities of people with disabilities. The research trends were identified using keyword frequency, centrality, and agglomeration structure analyses. Through this, we aimed to provide the basic data necessary to establish an oral health promotion plan for people with disabilities.

Materials and Methods

1.Ethics statement

This study utilizes existing data published in the RISS and has a low risk of research ethics. The data collected were secondary and did not contain any personal information.

2.Study design

Among the papers published in the RISS from 2000 to 2024, 70 papers with full text were selected from 147 papers searched using the keywords disabled and oral cavity.

The papers were organized according to author, title, journal, volume, year of publication, and keywords. Similar keywords were integrated and the final analysis was performed (Table 1).

Research Procedure and Contents

Research procedure Content Details of research
Research data collection Data collection ∙Disabled oral health research literature search: Author, title, journal, volume, year of publication, keyword summary
Analyze Key word analysis ∙Key word extraction, frequency analysis
Network analysis ∙Core node subject cluster analysis, Central structure analysis, cohesive structure analysis
Result Result interpretation ∙Result interpretation

3.Statistical methods

Network keyword analysis was performed using Netminer 4.0 software (Cyram, Co., Seongnam, Korea) The keyword frequency, connection centrality, and cohesive structure were analyzed. Keyword frequency analysis was conducted to identify important keywords in oral health research for disabled connection centrality analysis, which confirmed the organic connections between keywords by measuring the number of links between keywords. The narrower the spacing between keywords, the stronger the interrelationship14). Betweenness centrality analysis identified topics of oral research on people with disabilities. Cohesive structure analysis was used to analyze clustered keywords to identify close connections between keywords. Cohesive structure analysis is a keyword clustering classification in which intragroup links are greater than intergroup links. Modularity values range from –1 to 1, and if it appears as a positive number, modularity is appropriate15). Through cohesive structure analysis, the interrelationships of keywords were identified, and clustered concepts were derived. In this study, for Group 4, Step 70, the modularity value was 0.17.


1.Key word frequency analysis of the study subjects

There were 94 keywords presented in 70 academic papers related to the oral cavity of people with disabilities, and a total of 31 core keywords. Fourteen relatively important keywords were identified as 14 keywords with an occurrence frequency of three or higher. Table 2 shows the frequencies and ratios of the relevant keywords. The most frequently appearing topic in oral research on the disabled was oral health, with nine articles (9.5%). The following were dental caries, 8 articles (8.5%); DMFT (decayed-missing-filled-teeth), dental treatment, and oral health centers, 6 articles each (6.3%); and community oral health programs, 5 articles each (5.3%) (Table 2).

Key Word Frequency Analysis of the Study Subjects

Key word Numbera (%) Key word Numbera (%)
Oral health 9 (9.5) Physical disabilities 4 (4.2)
Dental caries 8 (8.5) Disabled children 4 (4.2)
DMFT 6 (6.3) Mental retardation 3 (3.1)
Dental treatment 6 (6.3) Feeding improvement activity program 3 (3.1)
Oral health center 6 (6.3) General anesthesia 3 (3.1)
Community oral health program 5 (5.3) National health survey 3 (3.1)
Admission facility 4 (4.2) intellectual disability 3 (3.1)

DMFT: decayed-missing-filled-teeth.

aNumber of studies containing keywords.

2.Study subjects’ results of degree centrality analysis

From the betweenness centrality analysis, the DMFT (0.426) was found to be the highest. Disabled children (0.278), special care dentistry (0.262), oral health behavior (0.229), periodontitis (0.213), and health insurance (0.180) appeared as research keywords with a high betweenness centrality (Table 3).

Study Subjects’ Results of Degree Centrality Analysis (n=115)

Key word Degree centrality Key word Degree centrality
DMFT 0.426 Type of disability 0.180
Disabled children 0.278 General anesthesia 0.163
Special care dentistry 0.262 Activity limitation 0.131
Oral health behavior 0.229 National health survey 0.131
Periodontitis 0.213 Impaired 0.131
Health insurance 0.180 Dental treatment 0.114

DMFT: decayed-missing-filled-teeth.

3.Study subjects’ cohesive structure analysis

The results of grouping keywords with high cohesion based on the modularity value presented in the community analysis are shown in Fig. 1. In this study, the modularity was 0.459. Fourteen community groups were identified. Table 4 shows the keywords of the six groups, excluding the individual groups. The results of the research on oral health for the disabled were as follows Group 1: oral diseases and functions of the disabled; Group 2: oral care for children with disabilities; Group 3: dental treatment for the disabled; Group 4: oral health policy; Group 5: oral care by dental hygienists; and Group 6: conservative dentistry.

Group Network Map Keyword

Group (number of keywords) Keyword (degreecentrality)
1 Oral diseases and Functions (13) Periodontitis (0.213), Gingivitis (0.114), First molar soundness (0.081), Occlusion (0.114), Oral function disorder (0.114), Oral functions (0.032), Oral health behavior (0.229), Communication process (0.081), Type of disability (0.180), Visually impaired (0.114), Disabled children (0.278), Living independence (0.032), Effect of education (0.016)
2 Oral care for children (11) School dental clinic (0.262), Pediatric dentistry (0.032), Dental caries (0.049), Dental caries prevention (0.098), Oral health (0.032), Brushing teeth (0.032), Regular oral examination (0.049), Awareness (0.049), Intellectual disability (0.016), Dental treatment (0.081), Guardians of disabled people (0.049), Multidisciplinary system (0.032)
3 Dental treatment for the disabled (11) DMFT (0.426), Special care dentistry (0.262) General anesthesia (0.163), Sedation (0.081), Dental treatment (0.081), Oral health promotion (0.081), Salivary pathogens (0.081), Frequency of treatment (0.081), Revisit intention (0.081), Oral health promotion (0.081), Revisit intention (0.081), Missing (0.032)
4 Oral health policy (6) Health insurance (0.180), National health survey (0.131), Activity limitation (0.131), Impaired (0.131), Mental retardation (0.065), Blindness and visual (0.049), Disorder grade (0.049)
5 Oral care by dental hygienists (3) Dental hygienist (0.016), Oral health center (0.032), Home visits (0.016)

DMFT: decayed-missing-filled-teeth.

Fig. 1. Cohesive structure analysis.

1.There were 13 keyword groups. The keywords were periodontitis (0.213), gingivitis (0.114), first molar soundness (0.081), occlusion (0.114), oral function disorder (0.114), and oral functions (0.032). These were grouped into research on oral diseases and the function of people with disabilities.

2.There were 11 group keywords, and the core keywords consisted of school dental clinic (0.262), pediatric dentistry (0.032), dental caries (0.049), and dental caries prevention (0.098). These were grouped into research on oral care for children with disabilities.

3.There were 11 group keywords, and the core keywords included DMFT (0.426), special care dentistry (0.262), general anesthesia (0.163), sedation (0.081), and dental treatment (0.081). These were grouped into research on dental treatments for disabled people.

4.There were six keyword groups: health insurance (0.180), national health survey (0.131), and activity limitation (0.131). These were grouped into research on health policies for people with disabilities.

5.There were three keyword groups: dental hygienists (0.016), oral health centers (0.032), and Home visits (0.016). This was grouped into research on oral care conducted by dental hygienists.

6.There were three keyword groups: dental caries (0.049), prosthetics (0.049), and simplified oral hygiene index (0.032). These were grouped into studies on tooth conservation (Table 4, Fig. 1).


1.Interpretation and comparison to previous studies

There was a difference in the frequency and betweenness centrality of the keywords. There were differences in the main keywords and betweenness centralities frequently used in research on oral health among people with disabilities. The most common keywords were DMFT and disabled children. Oral health, dental caries, dental treatment, and oral health centers appeared at a high frequency, but their centrality was low. The results of the betweenness centrality analysis showed that the order was disabled children, special-care dentistry, oral health behavior, periodontitis, and health insurance, indicating a high level of connectivity.

Community analysis results of research on disabled people: Group 1: oral disease and function for disabled people; Group 2: oral care for children with disabilities; Group 3: dental treatment for disabled people; Group 4: oral health policy; Group 5: oral care by dental hygienists; and Group 6: conservative dentistry.

Group 1 oral diseases and functions as disabilities consisted of keywords related to diseases such as periodontitis, gingivitis, and oral function disorder. Disabled people have different oral health conditions depending on their type and degree. Compared to non-disabled people, the frequency of oral diseases is high owing to a lack of oral health awareness and management skills16). In particular, elderly people with disabilities have poor self-care and are at high risk of aspiration pneumonia if they receive long-term care due to dysphagia, dry mouth, cerebrovascular disease, or dementia. However, the risk of oral problems increases in the absence of a guardian. People with disabilities’ right to health is legally guaranteed, and they must receive appropriate dental services17). Since various functions such as mastication, pronunciation, and aesthetics for disabled people are important factors that affect their quality of life18,19), various supports are needed to prevent oral diseases and maintain function.

Studies on oral care for Group 2 disabled children consisted of the following keywords: school dental clinic, pediatric dentistry, dental caries prevention, tooth brushing, and regular oral examination. It is difficult for the oral cavity to recover from damage; therefore, it is important to take care of it from an early age. Oral care should be practiced by preventing cavities, which occur frequently, and performing regular dental examinations. Medical staff must expand their experience through continuing education, such as learning about considerations in behavior control treatment and strengthening empathy20).

The oral health of people with disabilities cannot be improved with treatment alone. Preventive measures, such as tooth brushing education, fluoride, and sealants, are necessary. Therefore, dental hygienists are required at school oral health centers8). In some studies, it was found that participation in medical treatment for the disabled was influenced by education and volunteer experience. Therefore, there was a call for expanded participation in medical treatment and volunteer work for the disabled in university curricula2).

Dental treatment and tooth preservation for the disabled in Groups 3 and 6 consisted of special care dentistry, general anesthesia, sedation, and dental treatment. The proportion of dentists treating the disabled is only about 2.0% to 9.8%, and there are 51 oral health rooms in special schools nationwide and one tertiary medical institution in each region; therefore, there is a need to expand dentistry for the disabled to improve treatment accessibility8). Dentistry for non-disabled people is saturated, but dental care for disabled people is in short supply; therefore, sufficient medical services are not provided. When treating people with disabilities, medical staff must improve their negative awareness of medical risks and problems through patient cooperation during general anesthesia. In addition, the need to improve low oral health interest from the patients’ perspective and the problem of using medical institutions were presented using keywords such as frequency of treatment and revisit intention.

In some studies, conservative treatment was the most common form of dental treatment for people with disabilities, with 9.7 treatments per person21). In the past 10 years, the use of general anesthesia has increased in the field of pediatric dentistry, and to reduce the re-administration of general anesthesia for pediatric and adolescent patients, regular checkups and oral hygiene management22) have been expanded to promote oral health for the disabled. In addition, local centers need active promotion and system improvement so that disabled people can take an interest in and participate in oral health management. Oral health for disabled people should be comprehensively managed through online and offline platforms11).

It has been suggested that local centers need active promotion and system improvement so that disabled people can take interest in and participate in oral health care, and that the oral health of disabled people should be comprehensively managed through online and offline platforms11).

Group 4 comprised health insurance, national health survey, and activity limitations related to oral health policies. Based on the Oral Health Act and the Act on the Rights to Health for Persons with Disabilities, central, regional, and local oral centers for the disabled are being established and operated. Special school oral health projects, home-visit oral health management projects, and oral health mobile medical vehicle support projects are in progress. The government has presented the long-term goal of expanding the supply of quality public oral health services23). However, a policy approach is required to provide guardian education and onsite dental care for elderly and disabled people with nursing care insurance who are in the blind spot of oral care, support dental treatment costs for the disabled, and improve accessibility to dental services17).

Group 5 consisted of dental hygienists, oral health centers, and home visits. As the demand for professional manpower for the elderly and disabled is rapidly increasing, professional dental hygienists must be trained in home-visit oral care and care for the disabled at oral health centers11). Preventive care, such as regular checkups by a dental hygienist, fluoride application, dental fissure sealing, dental cleaning, and toothbrushing education10) can improve patients’ self-management capabilities and oral health6). The government recently introduced a system for attending physicians to promote oral health among people with disabilities. If dental hygienists are used, the rate of establishment of oral disease prevention plans, educational counseling, patient management, and visit service performance can be increased. However, strengthening the expertise in oral care education for the disabled through university and continuing education is required.

Local oral care centers for the disabled must provide medical treatment services for local residents, and oral education and examination programs tailored to the characteristics of people with disabilities. Meanwhile, the Central Medical Center for the Disabled develops and educates personnel dedicated to treating the disabled, develops and distributes oral health education materials according to the type of disability, and implements early prevention of oral diseases, promotion, and various survey projects to support the insufficient functions and roles of regional centers. However, this must be improved further24). Through an analysis of the research network related to the oral cavity of individuals with disabilities, we were able to identify research trends in six major concepts. Research on oral health policies for the disabled, treatment guidelines, professional training, and medical services required by the disabled is insufficient; therefore, improvements are required.


In this study, a network keyword analysis of the literature related to the oral cavity of the disabled was conducted. Because reports and policy reports from the Ministry of Health and Welfare were excluded, future research should supplement these reports to increase their generalizability. In addition, oral health research for the disabled has been conceptualized into six groups, but there is a need to supplement this in future research.


Oral research on the disabled has been conceptualized as oral diseases and functions of the disabled, oral care for disabled children, dental treatment for the disabled, oral health policies, and oral care by dental hygienists. Considering that the number of people with disabilities in a super-aging society will increase, there is a need to expand research that reflects oral health policies, treatment guidelines, training of oral health professionals, and the dental needs of people with disabilities to improve their oral health.



Conflict of interest

No potential conflict of interest relevant to this article was reported.

Ethical approval

This study was approved by the institutional review board of Konyang University (KYU-2024-006). The requirement to obtain informed consent was waived.



Data availability

Dataset 70 articles searched in PubMed.

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  2. Kim SY, Paik HR, Kim YJ: Developing dental service guideline for disabled patients - using service design methods -. Korean J Hosp Manag 22: 118-132, 2017.
  3. Choe CH: Dental services status of the disabled performed by dentists. J Korean Acad Oral Health 27: 59-71, 2003.
  4. Hwang SJ, Kim MJ, Song EJ: Case report : comparative study before and after oral health education program for people with developmental disabilities. J Korean Dent Hyg Sci 3: 45-50, 2020.
  5. Shim SH, Lee W, Choi B: The status and improvement course of dental treatment for the disabled in Korea. J Korean Dent Assoc 48: 280-287, 2010.
  6. Noh M, Oh H: Preliminary study on the establishment of dental treatment and follow-up management system under general anesthesia for patients with autism. J Korean Assoc Pers Autism 22: 183-199, 2022.
  7. Beck SJ, Sim OJ, Lee SM, Yun HS, Jeong TS, Kim JB: Evaluation of an incremental oral health care program by school dental clinic for disabled children in Changwon, Korea. J Korean Acad Oral Health 31: 60-72, 2007.
  8. Kim MJ, Jun EJ, Han DH, Jeong SH, Kim JB: Evaluation of oral health service program for disabled persons in Ulsan, Korea. J Korean Soc Dent Hyg 13: 297-303, 2013.
  9. Retrieved May 6, 2024, from, February 28).
  10. Yoon HS, Jeong MS, Jang JH: Changes in the oral health status of older adults with visual and hearing impairments through home oral health care intervention: a case report. J Korean Soc Dent Hyg 23: 13-23, 2023.
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  12. Jin HJ: Survey of unmet dental treatment needs among adult disabled. J Korea Acad Ind Coop Soc 16: 7501-7507, 2015.
  13. Min KC, Shin JY, Kim EH: Feeding disorders in autistic spectrum disorders. J Korean Acad Sens Integr 21: 79-102, 2023.
  14. Cho S, Shin H: The trend of academic research on high school credit system : network text analysis. Cult Converg 44: 149-167, 2022.
  15. Kim J: An essay for understanding the meaning of the network text analysis results in study of the public administration. J Humanit Soc Sci 16: 247-280, 2015.
  16. Ryu JI, Jeong HR: The analysis of dental treatments among the disabled in a charity dental clinic, Cheongju city. J Korean Acad Oral Health 46: 78-84, 2022.
  17. Huh J, Lee HG, Cheong J, Lee B, Jung HI: The current status and the future directions of dental services for disabled people. J Korean Acad Adv Gen Dent 9: 71-76, 2020.
  18. Hollister MC, Weintraub JA: The association of oral status with systemic health, quality of life, and economic productivity. J Dent Educ 57: 901-912, 1993.
    Pubmed CrossRef
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    Pubmed CrossRef
  20. Lee W, Kim YJ: A comparison study on dental treatment time of patients with different types of disabilities. J Korean Assoc Disabil Oral Health 10: 78-83, 2014.
  21. Jung YS, Choi YA, Kang JM, Lee YE, Song KB: Comparison of factors among the regional oral health center for the disabled in Korea. J Korean Soc Dent Hyg 21: 183-191, 2021.
  22. Lee A, Kim H, Song JS, et al.: Trends of dental treatment under general anesthesia and patterns of repeated general anesthesia in children and adolescents with severe disabilities. J Korean Acad Pediatr Dent 50: 75-88, 2023.
  23. Related Ministries Jointly: Oral health plan 2026, 2022∼2026. Retrieved May 6, 2024, from, June 9).
  24. National Evidence-based Healthcare Collaborating Agency (NECA): Exploring ways to develop oral public health policy. NECA, Seoul, pp.84-96, 2023.

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